/// <summary>
/// Process a transmitted message to import any signing certificates for subsequent S/MIME encryption.
/// </summary>
/// <param name="o">A ProcessMessageArguments object containing message parameters.</param>
private void ProcessMessage(object o)
{
ProcessMessageArguments arguments = (ProcessMessageArguments)o;
// Export the message to a local directory.
if (!string.IsNullOrEmpty(arguments.ExportDirectory))
{
string messageId = Functions.ReturnBetween(arguments.MessageText.ToLower(), "message-id: <", ">");
if (string.IsNullOrEmpty(messageId))
{
messageId = Guid.NewGuid().ToString();
}
string fileName = ProxyFunctions.GetExportFileName(arguments.ExportDirectory, messageId, arguments.InstanceId, arguments.UserName);
File.WriteAllText(fileName, arguments.MessageText);
}
// Only parse the message if it contains a known S/MIME content type.
string canonicalMessageText = arguments.MessageText.ToLower();
if (canonicalMessageText.IndexOf("application/x-pkcs7-signature") > -1 || canonicalMessageText.IndexOf("application/pkcs7-mime") > -1)
{
try
{
// Parse the message.
MailMessage message = new MailMessage(arguments.MessageText);
// If the message contains a signing certificate that we haven't processed on this session, import it.
foreach (X509Certificate2 cert in message.SmimeSigningCertificateChain)
{
if (cert != null && !SmimeCertificatesReceived.Contains(cert))
{
// Import the certificate to the Local Machine store.
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId, "Importing certificate with Serial Number {" + cert.SerialNumber + "}.", Proxy.LogLevel.Information, LogLevel);
CertHelper.InstallWindowsCertificate(cert, StoreLocation.LocalMachine);
// Remember this ceriticate to avoid importing it again this session.
SmimeCertificatesReceived.Add(cert);
}
}
}
catch (Exception ex)
{
if (arguments.DebugMode || System.Diagnostics.Debugger.IsAttached)
{
ProxyFunctions.Log(LogWriter, SessionId, "Exception while processing message: " + ex.ToString(), Proxy.LogLevel.Error, LogLevel);
}
else
{
ProxyFunctions.Log(LogWriter, SessionId, "Exception while processing message: " + ex.Message, Proxy.LogLevel.Error, LogLevel);
}
}
}
}
/// <summary>
/// Relay data read from one connection to another.
/// </summary>
/// <param name="o">A TransmitArguments object containing local and remote server parameters.</param>
private async void RelayData(object o)
{
// Cast the passed-in parameters back to their original objects.
TransmitArguments arguments = (TransmitArguments)o;
Stream clientStream = arguments.ClientStream;
Stream remoteServerStream = arguments.RemoteServerStream;
// A byte array to streamline bit shuffling.
char[] buffer = new char[Constants.SMALLBUFFERSIZE];
// Placeholder variables to track the current message being transmitted.
StringBuilder messageBuilder = new StringBuilder(Constants.SMALLSBSIZE);
// The overall number of bytes transmitted on this connection.
ulong bytesTransmitted = 0;
if (arguments.Credential != null)
{
UserName = arguments.Credential.UserName;
}
bool stillReceiving = true;
try
{
using (StreamReader clientStreamReader = new StreamReader(clientStream))
{
using (StreamWriter remoteServerStreamWriter = new StreamWriter(remoteServerStream))
{
remoteServerStreamWriter.AutoFlush = true;
while (Started && stillReceiving)
{
// Read data from the source and send it to its destination.
string stringRead = await clientStreamReader.ReadLineAsync();
if (stringRead != null)
{
int bytesRead = stringRead.Length;
bytesTransmitted += (ulong)bytesRead;
messageBuilder.AppendLine(stringRead);
// If this data comes from the client, log it. Otherwise, process it.
if (arguments.IsClient)
{
bool messageRelayed = false;
string[] commandParts = stringRead.Substring(0, stringRead.Length).Split(new char[] { ' ' }, 2);
// Optionally replace credentials with those from our settings file.
if (commandParts.Length == 2)
{
if (commandParts[0] == "USER")
{
if (arguments.Credential != null)
{
await remoteServerStreamWriter.WriteLineAsync("USER " + arguments.Credential.UserName);
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "C: USER " + arguments.Credential.UserName, Proxy.LogLevel.Raw, LogLevel);
messageRelayed = true;
}
else
{
UserName = commandParts[1];
}
}
else if (arguments.Credential != null && commandParts[0] == "PASS")
{
await remoteServerStreamWriter.WriteLineAsync("PASS" + arguments.Credential.Password);
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "C: PASS " + arguments.Credential.Password, Proxy.LogLevel.Raw, LogLevel);
messageRelayed = true;
}
}
if (LogLevel == Proxy.LogLevel.Verbose)
{
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "Command {" + commandParts[0] + "} processed.", Proxy.LogLevel.Verbose, LogLevel);
}
if (!messageRelayed)
{
await remoteServerStreamWriter.WriteLineAsync(stringRead);
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "C: " + stringRead, Proxy.LogLevel.Raw, LogLevel);
}
}
else
{
await remoteServerStreamWriter.WriteLineAsync(stringRead);
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "S: " + stringRead, Proxy.LogLevel.Raw, LogLevel);
// If we see a period between two linebreaks, treat it as the end of a message.
if (stringRead == ".")
{
string message = messageBuilder.ToString();
int endPos = message.IndexOf("\r\n.\r\n");
if (message.Contains("\r\n\r\n"))
{
int lastOkPos = message.LastIndexOf("+OK", endPos);
if (lastOkPos > -1)
{
message = message.Substring(message.IndexOf("\r\n", lastOkPos) + 2);
if (message.IndexOf("application/x-pkcs7-signature") > -1 || message.IndexOf("application/pkcs7-mime") > -1 || !string.IsNullOrEmpty(arguments.ExportDirectory))
{
Thread processThread = new Thread(new ParameterizedThreadStart(ProcessMessage));
processThread.Name = "OpaqueMail POP3 Proxy Signature Processor";
ProcessMessageArguments processMessageArguments = new ProcessMessageArguments();
processMessageArguments.MessageText = message.Substring(0, message.Length - 5);
processMessageArguments.ConnectionId = ConnectionId.ToString();
processMessageArguments.ExportDirectory = arguments.ExportDirectory;
processMessageArguments.InstanceId = arguments.InstanceId;
processMessageArguments.DebugMode = arguments.DebugMode;
processMessageArguments.UserName = UserName;
processThread.Start(processMessageArguments);
}
messageBuilder.Remove(0, endPos + 5);
}
}
messageBuilder.Clear();
}
}
}
else
{
stillReceiving = false;
}
}
}
}
}
catch (IOException)
{
// Ignore either stream being closed.
}
catch (ObjectDisposedException)
{
// Ignore either stream being closed.
}
catch (Exception ex)
{
// Log other exceptions.
if (arguments.DebugMode || System.Diagnostics.Debugger.IsAttached)
{
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId, "Exception while transmitting data: " + ex.ToString(), Proxy.LogLevel.Error, LogLevel);
}
else
{
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId, "Exception while transmitting data: " + ex.Message, Proxy.LogLevel.Error, LogLevel);
}
}
finally
{
// If sending to the local client, log the connection being closed.
if (!arguments.IsClient)
{
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId, "Connection from {" + arguments.IPAddress + "} closed after transmitting {" + bytesTransmitted.ToString("N0") + "} bytes.", Proxy.LogLevel.Information, LogLevel);
}
if (clientStream != null)
{
clientStream.Dispose();
}
if (remoteServerStream != null)
{
remoteServerStream.Dispose();
}
}
}
/// <summary>
/// Relay data read from one connection to another.
/// </summary>
/// <param name="o">A TransmitArguments object containing local and remote server parameters.</param>
private async void RelayData(object o)
{
// Cast the passed-in parameters back to their original objects.
TransmitArguments arguments = (TransmitArguments)o;
Stream clientStream = arguments.ClientStream;
Stream remoteServerStream = arguments.RemoteServerStream;
// A byte array to streamline bit shuffling.
char[] buffer = new char[Constants.SMALLBUFFERSIZE];
// Placeholder variables to track the current message being transmitted.
StringBuilder messageBuilder = new StringBuilder(Constants.SMALLSBSIZE);
// The overall number of bytes transmitted on this connection.
ulong bytesTransmitted = 0;
if (arguments.Credential != null)
UserName = arguments.Credential.UserName;
bool stillReceiving = true;
try
{
using (StreamReader clientStreamReader = new StreamReader(clientStream))
{
using (StreamWriter remoteServerStreamWriter = new StreamWriter(remoteServerStream))
{
remoteServerStreamWriter.AutoFlush = true;
while (Started && stillReceiving)
{
// Read data from the source and send it to its destination.
string stringRead = await clientStreamReader.ReadLineAsync();
if (stringRead != null)
{
int bytesRead = stringRead.Length;
bytesTransmitted += (ulong)bytesRead;
messageBuilder.AppendLine(stringRead);
// If this data comes from the client, log it. Otherwise, process it.
if (arguments.IsClient)
{
bool messageRelayed = false;
string[] commandParts = stringRead.Substring(0, stringRead.Length).Split(new char[] { ' ' }, 2);
// Optionally replace credentials with those from our settings file.
if (commandParts.Length == 2)
{
if (commandParts[0] == "USER")
{
if (arguments.Credential != null)
{
await remoteServerStreamWriter.WriteLineAsync("USER " + arguments.Credential.UserName);
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "C: USER " + arguments.Credential.UserName, Proxy.LogLevel.Raw, LogLevel);
messageRelayed = true;
}
else
UserName = commandParts[1];
}
else if (arguments.Credential != null && commandParts[0] == "PASS")
{
await remoteServerStreamWriter.WriteLineAsync("PASS" + arguments.Credential.Password);
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "C: PASS " + arguments.Credential.Password, Proxy.LogLevel.Raw, LogLevel);
messageRelayed = true;
}
}
if (LogLevel == Proxy.LogLevel.Verbose)
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "Command {" + commandParts[0] + "} processed.", Proxy.LogLevel.Verbose, LogLevel);
if (!messageRelayed)
{
await remoteServerStreamWriter.WriteLineAsync(stringRead);
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "C: " + stringRead, Proxy.LogLevel.Raw, LogLevel);
}
}
else
{
await remoteServerStreamWriter.WriteLineAsync(stringRead);
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "S: " + stringRead, Proxy.LogLevel.Raw, LogLevel);
// If we see a period between two linebreaks, treat it as the end of a message.
if (stringRead == ".")
{
string message = messageBuilder.ToString();
int endPos = message.IndexOf("\r\n.\r\n");
if (message.Contains("\r\n\r\n"))
{
int lastOkPos = message.LastIndexOf("+OK", endPos);
if (lastOkPos > -1)
{
message = message.Substring(message.IndexOf("\r\n", lastOkPos) + 2);
if (message.IndexOf("application/x-pkcs7-signature") > -1 || message.IndexOf("application/pkcs7-mime") > -1 || !string.IsNullOrEmpty(arguments.ExportDirectory))
{
Thread processThread = new Thread(new ParameterizedThreadStart(ProcessMessage));
processThread.Name = "OpaqueMail POP3 Proxy Signature Processor";
ProcessMessageArguments processMessageArguments = new ProcessMessageArguments();
processMessageArguments.MessageText = message.Substring(0, message.Length - 5);
processMessageArguments.ConnectionId = ConnectionId.ToString();
processMessageArguments.ExportDirectory = arguments.ExportDirectory;
processMessageArguments.InstanceId = arguments.InstanceId;
processMessageArguments.DebugMode = arguments.DebugMode;
processMessageArguments.UserName = UserName;
processThread.Start(processMessageArguments);
}
messageBuilder.Remove(0, endPos + 5);
}
}
messageBuilder.Clear();
}
}
}
else
stillReceiving = false;
}
}
}
}
catch (IOException)
{
// Ignore either stream being closed.
}
catch (ObjectDisposedException)
{
// Ignore either stream being closed.
}
catch (Exception ex)
{
// Log other exceptions.
if (arguments.DebugMode || System.Diagnostics.Debugger.IsAttached)
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId, "Exception while transmitting data: " + ex.ToString(), Proxy.LogLevel.Error, LogLevel);
else
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId, "Exception while transmitting data: " + ex.Message, Proxy.LogLevel.Error, LogLevel);
}
finally
{
// If sending to the local client, log the connection being closed.
if (!arguments.IsClient)
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId, "Connection from {" + arguments.IPAddress + "} closed after transmitting {" + bytesTransmitted.ToString("N0") + "} bytes.", Proxy.LogLevel.Information, LogLevel);
if (clientStream != null)
clientStream.Dispose();
if (remoteServerStream != null)
remoteServerStream.Dispose();
}
}
/// <summary>
/// Relay data read from one connection to another.
/// </summary>
/// <param name="o">A TransmitArguments object containing local and remote server parameters.</param>
private async void RelayData(object o)
{
// Cast the passed-in parameters back to their original objects.
TransmitArguments arguments = (TransmitArguments)o;
Stream clientStream = arguments.ClientStream;
Stream remoteServerStream = arguments.RemoteServerStream;
// A byte array to streamline bit shuffling.
char[] buffer = new char[Constants.SMALLBUFFERSIZE];
// Placeholder variables to track the current message being transmitted.
bool inMessage = false;
int messageLength = 0;
StringBuilder messageBuilder = new StringBuilder(Constants.SMALLSBSIZE);
// The overall number of bytes transmitted on this connection.
ulong bytesTransmitted = 0;
// When a "[THROTTLED]" notice was last received.
DateTime lastThrottleTime = new DateTime(1900, 1, 1);
if (arguments.Credential != null)
{
UserName = arguments.Credential.UserName;
}
bool stillReceiving = true;
try
{
using (StreamReader clientStreamReader = new StreamReader(clientStream))
{
using (StreamWriter remoteServerStreamWriter = new StreamWriter(remoteServerStream))
{
remoteServerStreamWriter.AutoFlush = true;
while (Started && stillReceiving)
{
// Read data from the source and send it to its destination.
string stringRead = await clientStreamReader.ReadLineAsync();
if (stringRead != null)
{
int bytesRead = stringRead.Length;
bytesTransmitted += (ulong)bytesRead;
// If this data comes from the client, log it. Otherwise, process it.
if (arguments.IsClient)
{
bool messageRelayed = false;
string[] commandParts = stringRead.Split(new char[] { ' ' }, 4);
if (commandParts.Length > 1)
{
// Optionally, transform the login details.
if (commandParts[1] == "LOGIN" && commandParts.Length == 4)
{
messageRelayed = TransformLogin(remoteServerStreamWriter, stringRead, arguments, ref UserName);
}
else
{
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "C: " + stringRead, Proxy.LogLevel.Raw, LogLevel);
}
// Remember the previous command.
if (commandParts[1].ToUpper() == "UID" && commandParts.Length > 2)
{
LastCommandReceived = (commandParts[1] + " " + commandParts[2]).ToUpper();
}
else
{
LastCommandReceived = commandParts[1].ToUpper();
}
// Stop after a logout order is received.
if (LastCommandReceived == "LOGOUT")
{
stillReceiving = false;
}
if (LogLevel == Proxy.LogLevel.Verbose)
{
switch (LastCommandReceived)
{
case "APPEND":
case "AUTHENTICATE":
case "CAPABILITY":
case "CHECK":
case "CLOSE":
case "COPY":
case "CREATE":
case "DELETE":
case "ENABLE":
case "EXAMINE":
case "EXPUNGE":
case "FETCH":
case "GETQUOTA":
case "GETQUOTAROOT":
case "LIST":
case "LOGIN":
case "LOGOUT":
case "LSUB":
case "MOVE":
case "NOOP":
case "NOTIFY":
case "RENAME":
case "SEARCH":
case "SELECT":
case "SETQUOTA":
case "STATUS":
case "STORE":
case "SUBSCRIBE":
case "UID COPY":
case "UID FETCH":
case "UID SEARCH":
case "UID STORE":
case "UNSUBSCRIBE":
case "XLIST":
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "Command {" + LastCommandReceived + "} processed.", Proxy.LogLevel.Verbose, LogLevel);
break;
}
}
}
// If the command wasn't processed, send the raw command.
if (!messageRelayed)
{
await remoteServerStreamWriter.WriteLineAsync(stringRead);
}
}
else
{
// If we're currently receiving a message, check to see if it's completed.
if (inMessage)
{
messageBuilder.AppendLine(stringRead);
if (messageBuilder.Length >= messageLength)
{
// If the message has been completed and it contains a signature, process it.
string message = messageBuilder.ToString(0, messageLength);
if (message.IndexOf("application/x-pkcs7-signature") > -1 || message.IndexOf("application/pkcs7-mime") > -1 || !string.IsNullOrEmpty(arguments.ExportDirectory))
{
Thread processThread = new Thread(new ParameterizedThreadStart(ProcessMessage));
processThread.Name = "OpaqueMail IMAP Proxy Signature Processor";
ProcessMessageArguments processMessageArguments = new ProcessMessageArguments();
processMessageArguments.MessageText = message;
processMessageArguments.ConnectionId = ConnectionId.ToString();
processMessageArguments.ExportDirectory = arguments.ExportDirectory;
processMessageArguments.InstanceId = arguments.InstanceId;
processMessageArguments.DebugMode = arguments.DebugMode;
processMessageArguments.UserName = UserName;
processThread.Start(processMessageArguments);
}
// We're no longer receiving a message, so continue.
inMessage = false;
messageBuilder.Clear();
}
}
else
{
// Disallow proxy stream compression.
if (stringRead.StartsWith("* CAPABILITY"))
{
stringRead = stringRead.Replace(" COMPRESS=DEFLATE", "");
}
// Check for IMAP meta flags.
string betweenBraces = Functions.ReturnBetween(stringRead, "[", "]");
switch (betweenBraces)
{
case "CLIENTBUG":
case "CORRUPTION":
case "OVERQUOTA":
case "SERVERBUG":
case "UNAVAILABLE":
ProxyFunctions.Log(LogWriter, SessionId, ConnectionId.ToString(), stringRead.Substring(stringRead.IndexOf("[")), Proxy.LogLevel.Warning, LogLevel);
break;
case "THROTTLED":
if (DateTime.Now - lastThrottleTime >= new TimeSpan(0, 20, 0))
{
ProxyFunctions.Log(LogWriter, SessionId, ConnectionId.ToString(), "Connection speed throttled by the remote server.", Proxy.LogLevel.Warning, LogLevel);
lastThrottleTime = DateTime.Now;
}
break;
}
// Messages are denoted by FETCH headers with their lengths in curly braces.
if (stringRead.ToUpper().Contains(" FETCH "))
{
int openBrace = stringRead.IndexOf("{");
if (openBrace > -1)
{
int closeBrace = stringRead.IndexOf("}", openBrace);
if (closeBrace > -1)
{
// Only proceed if we can parse the size of the message.
if (int.TryParse(stringRead.Substring(openBrace + 1, closeBrace - openBrace - 1), out messageLength))
{
inMessage = true;
}
}
}
}
}
await remoteServerStreamWriter.WriteLineAsync(stringRead);
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "S: " + stringRead, Proxy.LogLevel.Raw, LogLevel);
}
}
else
{
stillReceiving = false;
}
}
}
}
}
catch (IOException)
{
// Ignore either stream being closed.
}
catch (ObjectDisposedException)
{
// Ignore either stream being closed.
}
catch (Exception ex)
{
// Log other exceptions.
if (arguments.DebugMode || System.Diagnostics.Debugger.IsAttached)
{
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId, "Exception while transmitting data: " + ex.ToString(), Proxy.LogLevel.Error, LogLevel);
}
else
{
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId, "Exception while transmitting data: " + ex.Message, Proxy.LogLevel.Error, LogLevel);
}
}
finally
{
// If sending to the local client, log the connection being closed.
if (!arguments.IsClient)
{
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId, "Connection from {" + arguments.IPAddress + "} closed after transmitting {" + bytesTransmitted.ToString("N0") + "} bytes.", Proxy.LogLevel.Information, LogLevel);
}
if (clientStream != null)
{
clientStream.Dispose();
}
if (remoteServerStream != null)
{
remoteServerStream.Dispose();
}
}
}
/// <summary>
/// Relay data read from one connection to another.
/// </summary>
/// <param name="o">A TransmitArguments object containing local and remote server parameters.</param>
private async void RelayData(object o)
{
// Cast the passed-in parameters back to their original objects.
TransmitArguments arguments = (TransmitArguments)o;
Stream clientStream = arguments.ClientStream;
Stream remoteServerStream = arguments.RemoteServerStream;
// A byte array to streamline bit shuffling.
char[] buffer = new char[Constants.SMALLBUFFERSIZE];
// Placeholder variables to track the current message being transmitted.
bool inMessage = false;
int messageLength = 0;
StringBuilder messageBuilder = new StringBuilder(Constants.SMALLSBSIZE);
// The overall number of bytes transmitted on this connection.
ulong bytesTransmitted = 0;
// When a "[THROTTLED]" notice was last received.
DateTime lastThrottleTime = new DateTime(1900, 1, 1);
if (arguments.Credential != null)
UserName = arguments.Credential.UserName;
bool stillReceiving = true;
try
{
using (StreamReader clientStreamReader = new StreamReader(clientStream))
{
using (StreamWriter remoteServerStreamWriter = new StreamWriter(remoteServerStream))
{
remoteServerStreamWriter.AutoFlush = true;
while (Started && stillReceiving)
{
// Read data from the source and send it to its destination.
string stringRead = await clientStreamReader.ReadLineAsync();
if (stringRead != null)
{
int bytesRead = stringRead.Length;
bytesTransmitted += (ulong)bytesRead;
// If this data comes from the client, log it. Otherwise, process it.
if (arguments.IsClient)
{
bool messageRelayed = false;
string[] commandParts = stringRead.Split(new char[] { ' ' }, 4);
if (commandParts.Length > 1)
{
// Optionally replace credentials with those from our settings file.
if (commandParts[1] == "LOGIN" && commandParts.Length == 4)
{
if (arguments.Credential != null)
{
await remoteServerStreamWriter.WriteLineAsync(commandParts[0] + " " + commandParts[1] + " " + arguments.Credential.UserName + " " + arguments.Credential.Password);
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "C: " + commandParts[0] + " " + commandParts[1] + " " + arguments.Credential.UserName + " " + arguments.Credential.Password, Proxy.LogLevel.Raw, LogLevel);
messageRelayed = true;
}
else
UserName = commandParts[2].Replace("\"", "");
}
else
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "C: " + stringRead, Proxy.LogLevel.Raw, LogLevel);
if (commandParts[1].ToUpper() == "UID" && commandParts.Length > 2)
LastCommandReceived = (commandParts[1] + " " + commandParts[2]).ToUpper();
else
LastCommandReceived = commandParts[1].ToUpper();
if (LastCommandReceived == "LOGOUT")
stillReceiving = false;
if (LogLevel == Proxy.LogLevel.Verbose)
{
switch (LastCommandReceived)
{
case "APPEND":
case "AUTHENTICATE":
case "CAPABILITY":
case "CHECK":
case "CLOSE":
case "COPY":
case "CREATE":
case "DELETE":
case "ENABLE":
case "EXAMINE":
case "EXPUNGE":
case "FETCH":
case "GETQUOTA":
case "GETQUOTAROOT":
case "LIST":
case "LOGIN":
case "LOGOUT":
case "LSUB":
case "MOVE":
case "NOOP":
case "NOTIFY":
case "RENAME":
case "SEARCH":
case "SELECT":
case "SETQUOTA":
case "STATUS":
case "STORE":
case "SUBSCRIBE":
case "UID COPY":
case "UID FETCH":
case "UID SEARCH":
case "UID STORE":
case "UNSUBSCRIBE":
case "XLIST":
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "Command {" + LastCommandReceived + "} processed.", Proxy.LogLevel.Verbose, LogLevel);
break;
}
}
}
if (!messageRelayed)
await remoteServerStreamWriter.WriteLineAsync(stringRead);
}
else
{
// If we're currently receiving a message, check to see if it's completed.
if (inMessage)
{
messageBuilder.AppendLine(stringRead);
if (messageBuilder.Length >= messageLength)
{
// If the message has been completed and it contains a signature, process it.
string message = messageBuilder.ToString(0, messageLength);
if (message.IndexOf("application/x-pkcs7-signature") > -1 || message.IndexOf("application/pkcs7-mime") > -1 || !string.IsNullOrEmpty(arguments.ExportDirectory))
{
Thread processThread = new Thread(new ParameterizedThreadStart(ProcessMessage));
processThread.Name = "OpaqueMail IMAP Proxy Signature Processor";
ProcessMessageArguments processMessageArguments = new ProcessMessageArguments();
processMessageArguments.MessageText = message;
processMessageArguments.ConnectionId = ConnectionId.ToString();
processMessageArguments.ExportDirectory = arguments.ExportDirectory;
processMessageArguments.InstanceId = arguments.InstanceId;
processMessageArguments.DebugMode = arguments.DebugMode;
processMessageArguments.UserName = UserName;
processThread.Start(processMessageArguments);
}
// We're no longer receiving a message, so continue.
inMessage = false;
messageBuilder.Clear();
}
}
else
{
// Disallow proxy stream compression.
if (stringRead.StartsWith("* CAPABILITY"))
stringRead = stringRead.Replace(" COMPRESS=DEFLATE", "");
string betweenBraces = Functions.ReturnBetween(stringRead, "[", "]");
switch (betweenBraces)
{
case "CLIENTBUG":
case "CORRUPTION":
case "OVERQUOTA":
case "SERVERBUG":
case "UNAVAILABLE":
ProxyFunctions.Log(LogWriter, SessionId, ConnectionId.ToString(), stringRead.Substring(stringRead.IndexOf("[")), Proxy.LogLevel.Warning, LogLevel);
break;
case "THROTTLED":
if (DateTime.Now - lastThrottleTime >= new TimeSpan(0, 20, 0))
{
ProxyFunctions.Log(LogWriter, SessionId, ConnectionId.ToString(), "Connection speed throttled by the remote server.", Proxy.LogLevel.Warning, LogLevel);
lastThrottleTime = DateTime.Now;
}
break;
}
// Messages are denoted by FETCH headers with their lengths in curly braces.
if (stringRead.ToUpper().Contains(" FETCH "))
{
int openBrace = stringRead.IndexOf("{");
if (openBrace > -1)
{
int closeBrace = stringRead.IndexOf("}", openBrace);
if (closeBrace > -1)
{
// Only proceed if we can parse the size of the message.
if (int.TryParse(stringRead.Substring(openBrace + 1, closeBrace - openBrace - 1), out messageLength))
inMessage = true;
}
}
}
}
await remoteServerStreamWriter.WriteLineAsync(stringRead);
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId.ToString(), "S: " + stringRead, Proxy.LogLevel.Raw, LogLevel);
}
}
else
stillReceiving = false;
}
}
}
}
catch (IOException)
{
// Ignore either stream being closed.
}
catch (ObjectDisposedException)
{
// Ignore either stream being closed.
}
catch (Exception ex)
{
// Log other exceptions.
if (arguments.DebugMode || System.Diagnostics.Debugger.IsAttached)
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId, "Exception while transmitting data: " + ex.ToString(), Proxy.LogLevel.Error, LogLevel);
else
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId, "Exception while transmitting data: " + ex.Message, Proxy.LogLevel.Error, LogLevel);
}
finally
{
// If sending to the local client, log the connection being closed.
if (!arguments.IsClient)
ProxyFunctions.Log(LogWriter, SessionId, arguments.ConnectionId, "Connection from {" + arguments.IPAddress + "} closed after transmitting {" + bytesTransmitted.ToString("N0") + "} bytes.", Proxy.LogLevel.Information, LogLevel);
if (clientStream != null)
clientStream.Dispose();
if (remoteServerStream != null)
remoteServerStream.Dispose();
}
}
